Renewing a national treasure: INL’s Advanced Test Reactor undergoes sixth core overhaul

October 8, 2021, 3:31PMUpdated December 31, 2021, 4:16PMNuclear NewsJoseph Campbell; Photos by Joseph Campbell and Peter Ritchie, INL
The first of three phases of the Advanced Test Reactor’s sixth core overhaul culminated with the removal of the 31-ton stainless steel vessel top head on July 1, for the first time since 2004. The vessel and top head underwent extensive inspection, laser scanning, and upgrade as part of the overhaul. (Photo: JC)

As 2021 closes, Nuclear News is taking a look back at some of the feature articles published each month in the magazine. The October issue focused on plant maintenance and outage management with multiple articles looking at efficient ways to deal with plant maintenance. The article below looks at the herculean effort by INL to lead a full overhaul of the Advanced Test Reactor--a task that happens about every 10 years.

Out of the frenzy of nuclear technology and engineering development at the height of the Atomic Age, a few designs stand out above the rest—designs so innovative that they would not be surpassed for years, or even decades. An example of this unsurpassed design brilliance exists in the form of Idaho National Laboratory’s Advanced Test Reactor.

“ATR is really a beautiful machine,” said Sean O’Kelly, associate lab director for the ATR Complex. “The elegant cloverleaf core and control systems were a stroke of genius that solved just about every key problem of test reactor design. The designers’ solutions to those problems give us a testing capacity and flexibility that have yet to be matched.”

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